Like almost all foods, Jello can go bad. Unopened, dry Jello mix can last indefinitely at room temperature. Once the package has been opened, the mix will only last for three months, so if a recipe only calls for a little bit of Jello mix, you’ve still got some time to use the rest of the package!Click to see full answer. Just so, is it safe to use expired jello mix?Jello powder has a ‘best by’ date on the label, which is an estimate of how long the product should be of best quality. It will stay safe to use for a lot longer (years) when stored properly. Just make sure the product is stored in a cool and dry area (e.g. in the pantry) and it will be fine. cAN expired jello make you sick? When it comes to dry jello, it won’t spoil in a way that it makes you sick. And it’s basically up to you if you’re okay with eating slightly old and rubbery jello or you’d rather throw it out. Of course, the moment you notice any discolorations, like bacteria marks or specks of mold on the surface, discard the jello. how long is Jello good after expiration date? Jello has a best by date on the box, but it doesn’t just expire when that date comes around. The best by date is just a suggested date for when Jello will taste its best. Jello is good for up to 5 years after the best by date printed on the box.Can Jello shots go bad?Jello shots last in the refrigerator for three to five days. They can last even longer than that, but if you want them at their best, you should consume them within a couple days of making them.